git-annex/Annex/Action.hs
Joey Hess d3f78da0ed
propagate signals to the transferrer process group
Done on unix, could not implement it on windows quite.

The signal library gets part of the way needed for windows.
But I had to open https://github.com/pmlodawski/signal/issues/1 because
it lacks raiseSignal.

Also, I don't know what the equivilant of getProcessGroupIDOf is on
windows. And System.Process does not provide a way to send any signal to
a process group except for SIGINT.

This commit was sponsored by Boyd Stephen Smith Jr. on Patreon.
2020-12-11 15:32:00 -04:00

98 lines
2.4 KiB
Haskell

{- git-annex actions
-
- Copyright 2010-2020 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
{-# LANGUAGE CPP #-}
module Annex.Action (
action,
verifiedAction,
startup,
shutdown,
stopCoProcesses,
stopNonConcurrentSafeCoProcesses,
) where
import qualified Data.Map as M
import Annex.Common
import qualified Annex
import Annex.Content
import Annex.CatFile
import Annex.CheckAttr
import Annex.HashObject
import Annex.CheckIgnore
import Annex.TransferrerPool
import Control.Concurrent.STM
#ifndef mingw32_HOST_OS
import System.Posix.Signals
#endif
{- Runs an action that may throw exceptions, catching and displaying them. -}
action :: Annex () -> Annex Bool
action a = tryNonAsync a >>= \case
Right () -> return True
Left e -> do
warning (show e)
return False
verifiedAction :: Annex Verification -> Annex (Bool, Verification)
verifiedAction a = tryNonAsync a >>= \case
Right v -> return (True, v)
Left e -> do
warning (show e)
return (False, UnVerified)
{- Actions to perform each time ran. -}
startup :: Annex ()
startup = do
#ifndef mingw32_HOST_OS
av <- Annex.getState Annex.signalactions
let propagate sig = liftIO $ installhandleronce sig av
propagate sigINT
propagate sigQUIT
propagate sigTERM
propagate sigTSTP
propagate sigCONT
propagate sigHUP
-- sigWINCH is not propagated; it should not be needed,
-- and the concurrent-output library installs its own signal
-- handler for it.
-- sigSTOP and sigKILL cannot be caught, so will not be propagated.
where
installhandleronce sig av = void $
installHandler sig (CatchOnce (gotsignal sig av)) Nothing
gotsignal sig av = do
mapM_ (\a -> a (fromIntegral sig)) =<< atomically (readTVar av)
raiseSignal sig
installhandleronce sig av
#else
return ()
#endif
{- Cleanup actions. -}
shutdown :: Bool -> Annex ()
shutdown nocommit = do
saveState nocommit
sequence_ =<< M.elems <$> Annex.getState Annex.cleanupactions
stopCoProcesses
{- Stops all long-running child processes, including git query processes. -}
stopCoProcesses :: Annex ()
stopCoProcesses = do
stopNonConcurrentSafeCoProcesses
emptyTransferrerPool
{- Stops long-running child processes that use handles that are not safe
- for multiple threads to access at the same time. -}
stopNonConcurrentSafeCoProcesses :: Annex ()
stopNonConcurrentSafeCoProcesses = do
catFileStop
checkAttrStop
hashObjectStop
checkIgnoreStop